Squirrels are typically herbivores, eating mostly seeds and nuts. But some squirrels will eat insects and smaller vertebrates like birds and snakes. They cannot digest cellulose so they must rely on foods with a lot of protein, carbohydrates, and fats.
In many places, squirrels are considered pests. They often chew on various edible and inedible objects like fruits and vegetables in gardens, or electrical wires in an attic. Smell deterrents and traps are typically the best methods of getting rid of the bothersome pests.
In the face of danger, a squirrel will tend to stand motionless. Then it will usually search for a tree to climb up to hide.
In some parts of the United States, squirrel meat is considered a great meal. There are even cookbooks with recipes for squirrel meat. It can sometimes be a substitute for chicken or rabbit.